I am also facing issue auth not working after installing cordova-plugin-firebase-invites. If remove platform and uninstall the plugin for invite then after auth system is working perfectly.
returning below error.
2018-05-26 15:23:45.333437+0530 The Xavier’s Connect[5753:2255300] 4.13.0 - [Firebase/Core][I-COR000003] The default Firebase app has not yet been configured. Add [FIRApp configure]; (FirebaseApp.configure() in Swift) to your application initialization. Read more: https://goo.gl/ctyzm8.
2018-05-26 15:23:45.344879+0530 The Xavier’s Connect[5753:2254784] *** Terminating app due to uncaught exception ‘NSInternalInconsistencyException’, reason: ‘The default FIRApp instance must be configured before the default FIRAuthinstance can be initialized. One way to ensure that is to call [FIRApp configure]; (FirebaseApp.configure() in Swift) in the App Delegate’s application:didFinishLaunchingWithOptions: (application(_:didFinishLaunchingWithOptions:) in Swift).’
*** First throw call stack: